Novel contact etch stop film

ABSTRACT

A system and method for improved dry etching system. According to an embodiment, the present invention provides a partially completed integrated circuit device. The partially completed integrated circuit device includes a semiconductor substrate having a surface region. The partially completed integrated circuit device also includes an etch stop layer overlying the surface region. The etch stop layer is characterized by a thickness having at least a first thickness portion and a second thickness portion. The second thickness portion includes an etch stop surface region. The partially completed integrated circuit device additionally includes a silicon dioxide material provided within the first thickness portion of the etch stop layer. The partially completed integrated circuit device includes a silicon nitride material provided within the second thickness portion of the etch stop layer. In addition, the partially completed integrated circuit device includes a profile characterized by the silicon dioxide material in the first thickness portion changing to the silicon nitride material in the second thickness portion.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a division of U.S. application Ser. No.11/611,347, filed on Dec. 15, 2006, entitled “Novel Contact Etch StopFilm” (SMIC Docket No. 2005-00308-SH-US-DA1), which claims priority toChinese Patent No. 200610119026.30 filed on Nov. 30, 2006 (SMIC DocketNo. 1-05-308), both commonly assigned and hereby incorporated byreference for all purposes.

BACKGROUND OF THE INVENTION

The present invention is directed to integrated circuits and theirprocessing for the manufacture of semiconductor devices. Moreparticularly, the invention provides a method and a device for anetching process using an etch stop region for the manufacture ofintegrated circuits. Merely by way of example, the invention has beenapplied to the chemical dry etching process for the manufacture ofintegrated circuits. But it would be recognized that the invention has amuch broader range of applicability.

Integrated circuits or “ICs” have evolved from a handful ofinterconnected devices fabricated on a single chip of silicon tomillions of devices. Current ICs provide performance and complexity farbeyond what was originally imagined. In order to achieve improvements incomplexity and circuit density (i.e., the number of devices capable ofbeing packed onto a given chip area), the size of the smallest devicefeature, also known as the device “geometry”, has become smaller witheach generation of ICs. Semiconductor devices are now being fabricatedwith features less than a quarter of a micron across.

Increasing circuit density has not only improved the complexity andperformance of ICs but has also provided lower cost parts to theconsumer. An IC fabrication facility can cost hundreds of millions, oreven billions, of dollars. Each fabrication facility will have a certainthroughput of wafers, and each wafer will have a certain number of ICson it. Therefore, by making the individual devices of an IC smaller,more devices may be fabricated on each wafer, thus increasing the outputof the fabrication facility. Making devices smaller is very challenging,as each process used in IC fabrication has a limit. That is to say, agiven process typically only works down to a certain feature size, andthen either the process or the device layout needs to be changed. Anexample of such a limit is chemical dry etching process used for themanufacture of integrated circuits in a cost effective and efficientway.

Etching is an important process in semiconductor manufacturing. Etchinginvolves removing selected regions from the surface of a wafer using aplasma process that may include a physical process, chemical process, orthe combination thereof. Usually a goal of etching is to faithfullyreproduce masking patterns. To achieve this goal, it is often desirableto for the etching process to be highly selective both in patterns anddepth, which is often achieve through chemical dry etching.

Chemical drying etching usually involves generating reactive species inplasma, providing these species to the surface of material being etched,species being absorbed, reacting of these species on the surface to formvolatile by-product, absorbing or the by-product by the surface, anddiffusing of the desorbed species diffusing into gas. There are manyvarious dry-etch systems to accomplish these steps. For example,dry-etch systems include barrel etchers, downstream etchers,parallel-electrode (planar) reactor etchers, stacked parallel-electrodeetchers, hexode batch etchers, magnetron ion etchers, etc.

Regardless of type of dry-etch systems being used, an aspect for anetching process is a highly selective etching depth. There are variousmethods for controlling the etch depth. For example, a layer of “etchstop” may be used during the etching process to control etching depth.An etch stop layer is usually consisted of materials that featuredrastically different etch characteristics from the material to beetched. The etch stop layer is generally placed underneath the etchedmaterial to stop etching process.

Although the use of etch stop layers is fairly common, there are manylimitations. As an example, etch stop layers are often difficult to formfor providing selectivity between materials that may have commoncharacteristics. That is, it is often difficult to selectively removedifferent dielectric materials from each other. Depending uponapplication, convention etching process utilizing an etch stop layer mayadversely affect the characteristics of the wafer being etched.

Therefore, it is desirable to have an improved system and method foretching.

BRIEF SUMMARY OF THE INVENTION

According to the present invention, techniques directed to integratedcircuits and their processing for the manufacture of semiconductordevices are provided. More particularly, the invention provides a methodand device for an etching process using an etch stop region for themanufacture of integrated circuits. Merely by way of example, theinvention has been applied to the chemical dry etching process for themanufacture of integrated circuits. But it would be recognized that theinvention has a much broader range of applicability.

According to an embodiment, the present invention provides a partiallycompleted integrated circuit device, e.g., memory, microprocessor. Thepartially completed integrated circuit device includes a semiconductorsubstrate (e.g., silicon wafer, silicon on insulating, epitaxialsilicon) having a surface region. The partially completed integratedcircuit device also includes an etch stop layer overlying the surfaceregion. In a preferred embodiment, the etch stop layer is “graduated.”The term “graduated” is intended to mean that a certain concentration ofone or more species within a thickness of the etch stop layer changes ina graduated manner. Of course, this meaning is not intended to undulylimit the scope of the invention from any interpretation inconsistentwith those of ordinary skill in the art.

In a specific embodiment, the etch stop layer is characterized by athickness having at least a first thickness portion and a secondthickness portion. Depending upon the embodiment, there may also beother portions provided in the etch stop layer. The second thicknessportion includes an etch stop surface region, which include an entiresurface region or a portion of the surface region. The partiallycompleted integrated circuit device additionally includes a silicondioxide material (e.g., pure silicon dioxide, thermal oxide) providedwithin the first thickness portion of the etch stop layer. Additionally,the partially completed integrated circuit device includes a siliconnitride material (e.g., SiN) provided within the second thicknessportion of the etch stop layer. In addition, the partially completedintegrated circuit device includes a profile characterized by thesilicon dioxide material in the first thickness portion changing to thesilicon nitride material in the second thickness portion. Moreover, thepartially completed integrated circuit device includes an etchablematerial overlying the etch stop surface region. The etchable materialis characterized by a silicon dioxide bearing material.

According to another embodiment, the present invention provides a methodfor forming a contact region. The method includes the step of providinga substrate. The method additionally includes the step of forming anetch stop layer including a single continuous region having a puresilicon dioxide material in a first thickness portion, a siliconoxynitride material in a second portion, and a silicon nitride materialin a third thickness portion to form the etch stop layer. Additionally,the method includes forming an etchable material overlying the thirdthickness portion of the etch stop layer.

According to another embodiment, the present invention provides a methodof forming a single continuous etch stop layer on a partially completedintegrated circuit device comprising. The method includes the step ofproviding a substrate. The substrate is characterized by a siliconbearing material. The method also includes the step of introducing anoxygen bearing species to form a first thickness portion overlying thesubstrate. The first thickness portion is characterized by a silicondioxide material. The method additionally includes the step ofintroducing a nitrogen bearing species to form a second thicknessportion overlying the first thickness portion. The second thicknessportion is characterized by a silicon oxynitride material. The methodalso includes the step of removing oxygen bearing species to formsubstantially a third thickness portion overlying the second thicknessportion. The third thickness portion is characterized by a siliconnitride material. The single continuous etch stop layer is characterizedby a thickness having a first thickness portion, a second thicknessportion, and a third thickness portion.

It is to be appreciated that according to an embodiment, the presentinvention provides an improved etch stop layer to be used during theprocess of manufacturing integrated circuits. For example, the presentinvention provides good etch stop ability and good via contacts at thesame time. Moreover, according to an embodiment, the etch stop mechanismaccording to the present is relatively economical and practical tomanufacture.

Many benefits are achieved by way of the present invention overconventional techniques. For example, the present technique provides aneasy to use process that relies upon conventional technology. In someembodiments, the method provides a dry etch system. Additionally, themethod provides a process that is compatible with conventional processtechnology without substantial modifications to conventional equipmentand processes. Depending upon the embodiment, one or more of thesebenefits may be achieved. These and other benefits will be described inmore throughout the present specification and more particularly below.

Various additional objects, features and advantages of the presentinvention can be more fully appreciated with reference to the detaileddescription and accompanying drawings that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a simplified diagram illustrating a conventional etch stoplayer.

FIG. 1B is a simplified diagram illustrating a conventional partiallyprocessed substrate after the etching process and photoresist removal.

FIG. 2A is a simplified diagram illustrating a conventional etch stoplayer implemented with oxide material.

FIG. 2B is a simplified diagram illustrating a conventional partiallyprocessed substrate after the etching process and photoresist removal.

FIG. 3A is a simplified diagram illustrating an improved system for anetch system according to an embodiment of the present invention.

FIG. 3B illustrates a simplified diagram of an etch stop layer accordingto an embodiment of the present invention.

FIG. 3C is a simplified diagram illustrating a partially processedsubstrate after the etching process and photoresist removal according toan embodiment of the present invention.

FIG. 4 is a simplified diagram illustrating a method of manufacturing anetch stop layer according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to integrated circuits and theirprocessing for the manufacture of semiconductor devices. Moreparticularly, the invention provides a method and device for the etchingprocess for the manufacture of integrated circuits. Merely by way ofexample, the invention has been applied to the chemical dry etchingprocess for the manufacture of integrated circuits. But it would berecognized that the invention has a much broader range of applicability.

An important aspect for an etching process is a highly selective etchingdepth. There are various methods for controlling the etch depth. Forexample, a layer of “etch stop” may be used during the etching processto control etching depth. An etch stop layer is usually consisted ofmaterials that feature drastically different etch characteristic fromthe material to be etch. The etch stop layer is generally placedunderneath the etched material to stop etching process. Using etch stoplayer that is consisted of materials that that feature drasticallydifferent etch characteristic from the material to be etched has anadvantage of capable of effectively stopping the etching process.However, depending on the application, using etch stop layer that isconsisted of materials that that feature drastically different etchcharacteristic from the material to be etched also has disadvantages.For example, in applications where etching is used to create contact viathe etch stop layer may produce undesirable results.

FIG. 1A is a simplified diagram illustrating a conventional etch stoplayer. A prepared substrate material 100 been partially processed. Theprepared substrate material 100 includes a silicon layer 110, a nitridelayer 120, an inter dielectric (ILD) layer 130, and photoresists 140 aand 140 b. On top of the silicon layer 110 overlays the nitride layer120. The nitride layer 120 is used as an etch stop layer. On top of thenitride 120 is the ILD layer 130. During the etching process, the ILDlayer 130 is to be etched away during the etching process. The ILD layer130 is usually consisted of material such as silicon dioxide. On top ofthe ILD layer 130 are the photo resists 140 a and 140 b. Photoresists140 a and 140 b are used during the etching process to select whichareas are to be etched away. Photoresists 140 a and 140 b prevents areas130 a and 130 b of ILD layers that is directly underneath photoresists140 a and 140 b from being etched way during the etching process. Duringthe etching process, only the area 130 c of the ILD layer, which is notcovered by photoresists 140 a and 140 b, is etched way. When the ILDlayer 130 is etched away during the etching process, the nitride layer120 acts as an etch stop. Since nitride is drastically different fromsilicon dioxide, the plasma species that etches the ILD materials haslittle effect on the nitride. When the etching process is completed,photoresists 140 a and 140 b are removed.

FIG. 1B is a simplified diagram illustrating a conventional partiallyprocessed substrate after the etching process and photoresist removal.The partially processed substrate 150 includes ILD layers 160 a and 160b, a nitride layer 180, and a silicon layer 190. The ILD layers 160 aand 160 b are results of the etching process. For example, the ILD layer160 a corresponds to the areas 130 a of the ILD layer 130 in FIG. 1A.The area 130 a of the ILD layer 130 was blocked is blocked by thephotoresist 140 a from being etched away. Similarly, the ILD layer 160 bcorresponds to the areas 130 b of the ILD layer 130 in FIG. 1A. The area130 b of the ILD layer 130 was blocked is blocked by the photoresist 140b from being etched away. The area between the ILD layers 160 a and 160b are no longer present, as the area 130 c of the ILD layer in FIG. 1Ais etched away. During the etching process, the nitride layer 120 fromFIG. 1A effectively stops the etching process. Only a portion 170 of thenitride layer 180 is etched away. A portion 170 b of the nitride layer180 remains. The silicon layer 190 underneath the nitride layer 180remains unchanged by the etching process.

Etching process is often not perfectly selective. For example, in anapplication where the area 130 c of the ILD layer 130 in Figure isetched way to provide a space between the ILD layers 160 a and 160 b fora via plug to implement a gate for a MOS transistor, it is desirable toetch away nitride layer during the etching process so that a goodcontact between a gate metal and the silicon layer can be made. Becausethe nitride layer 120 in FIG. 1A effectively stops the plasma etching,only the portion 170 of the nitride layer 120 in FIG. 1A is etched away.The portion 170 b of the nitride layer 180 remains on top of the siliconlayer 190, creating an interface 170 a between the portion 170 b of thenitride layer 180 and the silicon layer 190. Depending uponapplications, the interface 170 a may have undesirable effects. Forexample, in an application where a gate metal contacts the portion 170 bof the nitride layer 180, electrical charges are trapped at theinterface 170 a, causing undesirable leakage and exhibit poor hotcarrier injection (HCI) characteristics. As an example, poor HCIcharacteristics usually leads to, inter alia, long-term degradation andpoor reliability. Therefore, it is desirable to eliminate the interface170 a between the nitride layer 170 and the silicon layer 180.

One way to reduce undesirable leakage and to improve HCI characteristicsis to eliminate the interface 170 a by using different material for theetch stop layer. For example, materials that have similarcharacteristics as the silicon layer may be used. FIG. 2A is asimplified diagram illustrating a conventional etch stop layerimplemented with oxide material. A prepared substrate material 200 beenpartially processed. The prepared substrate material 200 includes asilicon layer 240, a silicon dioxide layer 230, an ILD layer 220, andphotoresists 210 a and 210 b. On top of the silicon layer 240 overlaysthe silicon dioxide layer 230. The silicon dioxide layer 230 is used asan etch stop layer. On top of the silicon dioxide layer 230 is the ILDlayer 220. During the etching process, the ILD layer 220 is to be etchedaway during the etching process. The ILD layer 220 is usually consistedof material such as silicon dioxide. On top of the ILD layer 220 are thephotoresists 210 a and 210 b. Photoresists 210 a and 210 b are usedduring the etching process to select which areas are to be etched away.Photoresists 210 a and 210 b prevents areas 220 a and 220 b of ILDlayers 220 that is directly underneath photoresists 210 a and 210 b frombeing etched way during the etching process. During the etching process,only the area 220 c of the ILD layer, which is not covered byphotoresists 210 a and 210 b, is etched way. When the ILD layer 220 c isetched away during the etching process, the silicon dioxide layer 230acts as an etch stop. Since silicon oxide at the silicon dioxide layer230 is similar to the ILD layer 220 in material, a plasma species thatis effective against the ILD layer 220 is also effective against thesilicon dioxide layer 230, which is used as the etch stop layer. As aresult, the silicon dioxide layer 230 sometimes does not effectivelystop etching.

FIG. 2B is a simplified diagram illustrating a conventional partiallyprocessed substrate after the etching process and photoresist removal.The partially processed substrate 250 includes ILD layers 260 a and 260b, silicon oxide layers 270 a and 270 b, and a silicon layer 280. TheILD layers 260 a and 260 b are results of the etching process. Forexample, the ILD layer 260 a corresponds to the areas 220 a of the ILDlayer 220 in FIG. 2A. The area 220 a of the ILD layer 220 was blocked isblocked by the photoresist 210 a from being etched away. Similarly, theILD layer 260 b corresponds to the areas 220 b of the ILD layer 220 inFIG. 2A. The area 220 b of the ILD layer 220 was blocked is blocked bythe photoresist 210 b from being etched away. The area between the ILDlayers 260 a and 260 b are no longer present, as the area 220 c of theILD layer 220 in FIG. 2A is etched away. During the etching process, thesilicon dioxide layer 230 from FIG. 2A does not effectively stop theetching process. As a result, as shown on FIG. 2B, the silicon dioxide230 layer from FIG. 2A is etched through, leaving a gap between siliconoxide layer 270 a and 270 b. In addition, because of the poor etchstopping capability of the silicon dioxide layer 230, a portion 290 ofthe silicon layer 280 is also etched away. The partially processsubstrate 250 does not have an interface between a nitride layer and asilicon layer as seen on the partially processed substrate 150. However,since the portion 290 of the silicon layer 280 is etched away, thepartially processed substrate 250 provides a poor via contact. Forexample, the partially processed substrate 250 may have junction leakagebecause the portion 290 of the silicon layer 280 is etched away. Becausethe poor capability in effectively stopping the etching process, silicondioxide is usually not used as a material for etch stop.

Therefore, it is desirable to have an improved etch stop that providesgood etch stopping capability and good contact at the same time.

FIG. 3A is a simplified diagram illustrating an improved system for anetch system according to an embodiment of the present invention. Thisdiagram is merely an example, which should not unduly limit the scope ofthe claims. One of ordinary skill in the art would recognize manyvariations, alternatives, and modifications. The prepared substratematerial 300 includes a silicon layer 340, an etch stop layer 330, anILD layer 320, and photoresists 310 a and 310 b. On top of the siliconlayer 340 overlays the etch stop layer 330. The silicon dioxide layer330 is used as an etch stop layer. On top of the etch stop layer 330 isthe ILD layer 320. During the etching process, the ILD layer 320 is tobe etched away during the etching process. The ILD layer 320 is usuallyconsisted of material such as silicon dioxide. On top of the ILD layer320 are the photoresists 310 a and 310 b. Photoresists 310 a and 310 bare used during the etching process to select which areas are to beetched away. Photoresists 310 a and 310 b prevents areas 320 a and 320 bof ILD layers 320 that is directly underneath photoresists 310 a and 310b from being etched way during the etching process. During the etchingprocess, only the area 320 c of the ILD layer, which is not covered byphotoresists 310 a and 310 b, is etched way. When the ILD layer 320 c isetched away during the etching process, the etch stop layer 330 acts asan etch stop. According to an embodiment of the present invention, theetch stop layer 330 consists of different materials in accordance to agraduated profile.

FIG. 3B illustrates a simplified diagram of an etch stop layer accordingto an embodiment of the present invention. This diagram is merely anexample, which should not unduly limit the scope of the claims. One ofordinary skill in the art would recognize many variations, alternatives,and modifications. According to an embodiment, the etch stop layer 330has a thickness of approximately 410 angstroms. The etch stop layer 330consists of different materials according to a profile 338. In apreferred embodiment, the profile 335 is continuously graduated.According to the profile 338, the top portion 332 of the etch stop layer330 consists substantially entirely of silicon nitride. The bottomportion 335 of the etch stop layer 330 consists substantially entirelyof silicon dioxide. The material make up of the etch stop layer 330gradually changes from silicon dioxide at the bottom portion 335 to thesilicon nitride at the top portion 332. For example, the middle portion336 includes silicon oxynitride material. At the top end of the middleportion 336, the silicon oxynitride material includes more nitride andless oxide. At the bottom end of the middle portion 336, the siliconoxynitride material includes more oxide and less nitride.

FIG. 3C is a simplified diagram illustrating a partially processedsubstrate after the etching process and photoresist removal according toan embodiment of the present invention. This diagram is merely anexample, which should not unduly limit the scope of the claims. One ofordinary skill in the art would recognize many variations, alternatives,and modifications. The partially processed substrate 300 includes ILDlayers 320 a and 320 c, an etch stop layer 330, and a silicon layer 340.The ILD layers 320 a and 320 b are results of the etching process. Forexample, the ILD layer 320 a corresponds to the areas 320 a off the ILDlayer 320 in FIG. 3 a. The area 320 a of the ILD layer 320 was blockedis blocked by the photoresist 310 a from being etched away. Similarly,the ILD layer 320 b corresponds to the areas 320 b of the ILD layer 320in FIG. 2A. The area 320 b of the ILD layer 320 was blocked is blockedby the photoresist 310 b from being etched away. The area between theILD layers 320 a and 320 b are no longer present, as the area 320 c ofthe ILD layer 320 in FIG. 3 a is etched away. During the etchingprocess, a portion 330 a of the etch stop layer 330 is also etched away.Because the portion 330 a is primarily consisted for silicon nitride,the top portion effectively stops the etching process, which is to etchaway the ILD layer 320. As seen on FIG. 3C, the lower portion 330 b ofthe etch stop layer 330 is not etched away and remains on the partiallyprocess substrate 300. As merely an example, the etch stop layer hasbeen described throughout the present specification and moreparticularly below.

An embodiment of etch stop layer according to the present invention issuperior than etch stopping mechanisms illustrated according FIG. 1A andFIG. 2A. For example, compared to the nitride based etch stop layer asillustrated according to FIG. 1 a, the etch stop layer 330 does notshare an interface between nitride and silicon. The contact between theetch stop layer 330 and the underlying silicon layer 340 is an interface350, which is an interface between silicon and silicon dioxide.Depending on applications, the interface 350, because of the similaritybetween silicon and silicon, does not trap electrons and providesexcellent between the silicon layer 340 and a gate metal. As a result,good HCI characteristics are achieved. According to an embodiment, thepresent invention is also superior than the etch stopping mechanism asillustrated at FIG. 2A. For example, because the etch stop layer 330 isconsisted primarily of nitride at its top portion 332, the etch stoplayer 330 offers much better etch stop capability compared to thesilicon dioxide etch stop layer on FIG. 2A. The silicon layer 340 is notetched away at all.

FIG. 4 is a simplified diagram illustrating a method of manufacturing anetch stop layer according to an embodiment of the present invention.This diagram is merely an example, which should not unduly limit thescope of the claims. One of ordinary skill in the art would recognizemany variations, alternatives, and modifications. The manufacturingmethod 400 starts at step 410. At step 420, a substrate that consistsprimarily of silicon is provided. For example, the substrate is thesilicon layer 340 in FIG. 3A. Next, at step 430, silicon dioxide isgrown from the substrate. For example, the substrate is subjected tooxygen gas at a high temperature for the silicon dioxide to grow. Atstep 440, concentration of oxygen gas is reduced and nitrogen gas isintroduced. For example, silicon oxynitride material is grown on top thesilicon dioxide. According to an embodiment, the make up of the siliconoxynitride material is associated with the concentration and the ratiothereof of nitrogen and oxygen gases. At step 450, the substrate issubject to only nitrogen gas, and silicon nitride is grown. At step 460where the growing of etch stop layer stops, an etch layer with a profileis formed. For a preferred embodiment, the profile is continuouslygraduated. For example, the etch stop layer 330 in FIG. 3B is formed atstep 460. The etch stop layer 330 consists of different materialsaccording to the profile 338. According to the profile 338, the topportion 332 of the etch stop layer 330 consists substantially entirelyof silicon nitride. The bottom portion 335 of the etch stop layer 330consists substantially entirely of silicon dioxide. The material make upof the etch stop layer 330 gradually changes from silicon dioxide at thebottom portion 335 to the silicon nitride at the top portion 332. Afterthe etch stop layer is formed, etchable material is provided at step470. For example, etchable material is the ILD layer material thatconsists primarily of silicon dioxide.

FIG. 4A is merely an example, which should not unduly limit the scope ofthe claims. One of ordinary skill in the art would recognize manyvariations, alternatives, and modifications. For example, after etchablematerial is provided at step 470, photoresists is added on top of theetchable material.

According to an embodiment, the present invention provides a partiallycompleted integrated circuit device. The partially completed integratedcircuit device includes a semiconductor substrate having a surfaceregion. The partially completed integrated circuit device also includesan etch stop layer overlying the surface region. The etch stop layer ischaracterized by a thickness having at least a first thickness portionand a second thickness portion. The second thickness portion includes anetch stop surface region. The partially completed integrated circuitdevice additionally includes a silicon dioxide material provided withinthe first thickness portion of the etch stop layer. Additionally, thepartially completed integrated circuit device includes a silicon nitridematerial provided within the second thickness portion of the etch stoplayer. In addition, the partially completed integrated circuit deviceincludes a profile characterized by the silicon dioxide material in thefirst thickness portion changing to the silicon nitride material in thesecond thickness portion. Moreover, the partially completed integratedcircuit device includes an etchable material overlying the etch stopsurface region. The etchable material is characterized by a silicondioxide bearing material. For example, the partially completedintegrated circuit device may be implement according to FIG. 3.

According to another embodiment, the present invention provides a methodfor forming a contact region. The method includes the step of providinga substrate. The method additionally includes the step of forming anetch stop layer including a continuous region having a pure silicondioxide material in a first thickness portion, a silicon oxynitridematerial in a second portion, and a silicon nitride material in a thirdthickness portion to form the etch stop layer. Additionally, the methodincludes forming an etchable material overlying the third thicknessportion of the etch stop layer. For example, the method for forming acontact region may be implement according to FIG. 3.

According to another embodiment, the present invention provides a methodof forming a etch stop layer on a partially completed integrated circuitdevice. The method includes the step of providing a substrate. Thesubstrate is characterized by a silicon bearing material. The methodalso includes the step of introducing an oxygen bearing species to forma first thickness portion overlying the substrate. The first thicknessportion is characterized by a silicon dioxide material. The methodadditional includes the step of introducing an nitrogen bearing speciesto form a second thickness portion overlying the first thicknessportion. The second thickness portion is characterized by a siliconoxynitride material. The method also includes the step of removingoxygen bearing species to form substantially a third thickness portionoverlying the second thickness portion. The third thickness portion ischaracterized by a silicon nitride material. The etch stop layer ischaracterized by a thickness having a first thickness portion, a secondthickness portion, and a third thickness portion. For example, themethod of forming an single continuous etch stop layer on a partiallycompleted integrated circuit device may be implement according to FIG.3.

It is to be appreciated that according to an embodiment, the presentinvention provides an improved etch stop layer to be used during theprocess of manufacturing integrated circuits. For example, the presentinvention provides good etch stop ability and good via contacts at thesame time. Moreover, according to an embodiment, the etch stop mechanismaccording to the present is relatively economical and practical tomanufacture.

It is also understood that the examples and embodiments described hereinare for illustrative purposes only and that various modifications orchanges in light thereof will be suggested to persons skilled in the artand are to be included within the spirit and purview of this applicationand scope of the appended claims.

1-8. (canceled)
 9. A method for forming a contact region for anintegrated circuit device, the method comprising: providing a substrate;forming an etch stop layer including a single continuous region having apure silicon dioxide material in a first thickness portion, a siliconoxynitride material in a second portion, and a silicon nitride materialin a third thickness portion to form the etch stop layer; forming anetchable material overlying the third thickness portion of the etch stoplayer.
 10. The method of claim 9 wherein the forming an etch stop layeris performed in a single chamber.
 11. The method of claim 9 wherein theforming an etch stop layer is performed in vacuum.
 12. The method ofclaim 9 further comprising forming at least one photoresist overlyingthe etchable material.
 13. The method of claim 9, wherein the thirdthickness portion includes an etch stop surface region.
 14. The methodof claim 9, wherein the silicon dioxide material comprises a SiO2material and the silicon nitride comprises a SiN material.
 15. Themethod of claim 9, wherein the substrate consists of silicon material.16. The method of claim 9, wherein the etchable material ischaracterized by a silicon dioxide bearing material.
 17. The method ofclaim 9 wherein the etch stop layer is overlying a surface region of thesubstrate.
 18. The method of claim 9 wherein the etch stop layer is onand in contact with a surface region of the substrate.
 19. A method offorming a single continuous etch stop layer for an integrated circuitdevice comprising: providing a substrate, the substrate beingcharacterized by a silicon bearing material; introducing an oxygenbearing species to form a first thickness portion overlying thesubstrate to cause the first thickness portion to be characterized by asilicon dioxide material; introducing an nitrogen bearing species toform a second thickness portion overlying the first thickness portion tocause the second thickness portion to be characterized by a siliconoxynitride material; changing a concentration of the oxygen bearingspecies to form a third thickness portion overlying the second thicknessportion to cause the third thickness portion to be characterized by asilicon nitride material; andwhereupon at least the first thicknessportion, the second thickness portion, and the third thickness portionforms an etch stop layer having a total thickness.
 20. The method ofclaim 19 wherein the total thickness is less than 410 Angstroms.
 21. Themethod of claim 19 wherein the introducing an oxygen bearing speciescomprises subjecting an oxygen gas to a microwave source.
 22. The methodof claim 19 wherein the introducing a nitrogen bearing species comprisessubjecting a nitrogen gas to a microwave source.